code: def encode_schema(schema: Dict[str, SchemaField]) -> str:
      copy_schema = schema.copy()
  
      for k, v in copy_schema.items():
          copy_schema[k] = v.to_dict()  # type: ignore
  
      return json.dumps(copy_schema, cls=EnumEncoder)
  
imports: from collections import namedtuple
  from io import BytesIO
  import numpy
  from itertools import chain, islice
  from enum import Enum
  import json
  from bigdl.dllib.utils.log4Error import *
  from typing import Any, Dict, Iterator, List, Union, TYPE_CHECKING
label_desc: Use image node_id 3 for calling a global function with example usage: encode_schema(schema) and returns: json